I dislike the contrast the author, Lee McIntyre, tries to make between his talking to deniers and the marches for science. They are both valuable, one method will not do the job when it comes to social change.

Lee McIntyre makes the friendly case for asking questions. As a climate scientist I also noticed how effective this is on social media because it makes the deniers do the work, rather than having to type up years of academic eduction. When asking questions it quickly becomes apparent how little they know, which is useful to open minds and useful to see for the audience. (This especially works if you go in depth and stay on topic; deny the person you are talking with the option of changing topics to keep the conversation superficial, sprout a large number of accusations and hope something will stick with the audience.)

The article does a better job in convincing that it works to listen and talk to normal folks who have been conned by the anti-science activists than to show you can reach the worst extremists. Also the settings Lee talks about are rather private. On social media there will be a much larger audience than the person you are talking with, that changes their behavior (makes public change and admission you had a point less likely) and makes it much more valuable to ensure that the audience is helped by the conversation than that the person you are talking with changes their mind.